<template>
    <div class="todo-header ">
        <input type="text" placeholder="请输入任务名称，按回车键确认" v-model="title" @keyup.enter="add">
    </div>
</template>
<script>
    import {nanoid} from 'nanoid'
    export default {
        name:"MyHeader",
        data(){
            return{
                title:''
            }
        },
        methods: {
            add(e){
                //校验数据
                if(!this.title.trim())return alert('输入不能为空')
                //将用户的输入包装成一个todo对象
                const obj = {
                    id:nanoid(),
                    title:this.title,
                    done:false
                };
                // 通知App组件去添加一个todo对象
                this.$emit('addTodo',obj)
                // 清空输入
                this.title=""
            }
        },
    }
</script>
<style scoped lang="less">
    .todo-header input{
        width: 560px;
        height: 28px;
        font-size: 14px;
        border:1px solid #ccc;
        border-radius: 4px;
        padding:4px 7px;
    }
    .todo-header input:focus{
        outline: none;
        border-color: rgba(82,168,236,0.8);
        box-shadow: inset 0 1px 1px rgba(0,0,0,0.075),0 0 8px rgba(82,168,236,0.8);
    }
</style>